The importance of requiring the knowledge of a number of processes and the ability to visualize how they operate in concert is described.
Recursion is the act of defining an object or solving a problem in terms of (a smaller or modified version) of the original problem.
In this sense, I think programs can be thought of as manifest mathematics which can lead to experience Math through other senses than just by seeing symbols and unravelling them in your head. This invokes the metaphor, computers as an exobrain for Mathematics